1. Field of the Invention
An apparatus consistent with the present invention relates to a pressure and vibration sensing apparatus designed to sense pressure together with vibration through a unitary device.
2. Description of the Related Art
Generally, a cleaning apparatus employing water, such as a washing machine or a dish washer, comprises a level sensor to detect water level in the cleaning apparatus when supplying the water into the apparatus. As for such a level sensor, a pressure sensor to sense pressure variation caused by variation in water level is typically used. Furthermore, the cleaning apparatus comprises a vibration sensor to detect vibration generated when the cleaning apparatus is operated.
There are many applications, which separately include the pressure sensor and the vibration sensor for the purpose of sensing the pressure and the vibration. For instance, as for such an application, there are a tank for storing hazardous materials sensitive to pressure or vibration, such as flammable chemical materials, wind tunnel test equipment in a laboratory required to sense wind pressure and vibration, and the like.
However, conventionally, the pressure and vibration sensors are separately manufactured, and then disposed in the apparatus. Thus, the number of components in the apparatus having these sensors is increased, thereby complicating the construction of the apparatus and increasing manufacturing costs.
In order to solve the aforementioned problem, Korean Patent No. 10-338262 issued on May 27, 2002 discloses a sensor for detecting water level and vibration, wherein pressure and vibration detection can be performed through a unitary device. The sensor for detecting the water level and the vibration disclosed in Korean Patent No. 10-338262 comprises: a diaphragm deformable according to air pressure variation caused by variation in water level in a washing machine; a core displaceable according to a deformation state of the diaphragm; a case encasing the diaphragm and the core; and a coil disposed in the case in such a manner that the case surrounds the coil to detect displacement of the core.
The sensor for detecting the water level and the vibration further comprises a vibration sensing part provided to define a predetermined space in one side of the core and having a sloped surface, and a rolling member movably disposed in the vibration sensing part. Accordingly, when the vibration is generated in a machine, the rolling member in the vibration sensing part induces an inductance variation in the coil while moving along the sloped surface of the vibration sensing part, sensing the vibration.
The sensor for detecting the water level and the vibration is integrated into one body so as to sense the water level along with the vibration. However, since the sensor comprises the diaphragm, the core, and the coil, as components to sense the pressure variation according to the variation in water level, and comprises the vibration sensing part having the sloped surface and the rolling member as components to sense the vibration, a lot of components are provided in the sensor, thereby complicating the construction and increasing the manufacturing costs. Furthermore, since the sensor adopts a principle of sensing vibration caused by movement of the rolling member when the vibration is generated in a machine, it is difficult to sense a minute vibration and the magnitude thereof.